Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the description does not need to repeat those. It adds valuable context beyond annotations: the payment mechanism (prepaid credit per consultation), the lack of platform credentials, and the LGPD compliance statement about data control. These explain the operational and legal behavior of the tool, complementing the annotations without contradiction.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is composed of four sentences, each adding distinct information: purpose, hosting/payment, data source and privacy, and LGPD responsibility. It front-loads the main action (querying the certificate) and keeps additional details brief. No redundant or filler sentences are present, making it appropriately sized for a read-only query tool.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple tool with two parameters and no output schema, the description covers the core purpose, cost, and data governance but omits critical usage details like parameter semantics, response format, or any limitations (e.g., state scope). Since there is no output schema, it should describe what is returned, but it does not. The description is adequate for basic understanding but incomplete for agent guidance on invocation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema lists only 'cpf' and 'cnpj' with no descriptions, and schema description coverage is 0%. The description does not explain what these parameters represent or how to use them (e.g., which one is needed, if both are acceptable, or if either is required). Since the description must compensate for the lack of schema documentation, this is a significant gap. The tool name and purpose hint at CPF/CNPJ identifiers but do not clarify usage.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool queries the 'Certidao de Regularidade' (Certificate of Regularity) from SEFAZ CE. It names the specific resource, the official source, and the action ('consulta em fonte oficial'). It distinguishes itself from sibling tools (which are platform-wide utilities like authenticate or connect) by being a domain-specific query.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides context on usage constraints: it is 'hosted by the platform, without platform credentials', requires prepaid credit per query, and is for official data. However, it does not explicitly state when to use this tool over alternatives or when not to use it. It implies usage for legitimate LGPD-compliant purposes but lacks concrete exclusions or alternative tool references.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.